Ok a bit of history first I've never built a Model A hot rod before so I'm venturing into uncharted areas on somethings. I am building a 1928 Model A RPU. Stock 4 banger, hydraulic brakes and basically a stock front end save for a set of split bones and reversed eye spring. I have the front end all assembled and I notice that the tie rod end hits the bones when I move it side to side. So my question is what am I doing wrong? Do I need to go with a different spindle? Is there a different setup I could use to lower the tie rod beneath the bones? Looking for suggestions. Thanks
My guess is that splitting the bones caused your problem. Can you move the bone to the original position and see if it solves the problem? Why did you split them? Charlie Stephens
As Charlie said, can you mount the bones back under? Also if you split the model A bones and have them running back level with the ground you will have approx. 1 1/4 degrees of caster.
If you are running a four banger and original gearbox, or a later 3spd with the Clings adapter i would be running the stock wishbone underneath. The Clings kit comes with a wishbone mount. There's no real need to split the bones with a banger.
Mount the brackets on inside of frame and also run the bones tie rods from back side also. May be enough to clear. Posted using the Full Custom H.A.M.B. App!
You really need a practical reason to split bones (like a non-stock transmission that won't fit with the bones in their stock location), otherwise there is no point to doing it. Like others have suggested, go to a stock wishbone setup if you can.
If the problem occurs at the end of the tie rod where it is larger can you use a "modern" type of tie rod and ball joint that would be smaller at the end? Charlie Stephens
You will get your tie rod clearance, but will loose your drag-link and steering arm clearances. A drop axle necessitates modifying the steering arms or swapping spindles that will clear the axle. Changing one 'little' thing starts a chain reaction of modifications on these cars... I'll jump on the bandwagon and ask why you split the bones? Posted using my Lil' Orphan Annie Secret Society Decoder Pin
Either; a) do as these guys have said (use a stock wishbone), or b) heat and bend the steering arms down and put the tie rod sufficiently below the split bones. I did b on mine.
The easiest way to adapt '40 Ford style hydraulic brakes is to use '40 Ford spindles and kingpins on the A axle. And you would also probably use the '40 tie rod and modern-ish ends. Lots more clearance around your wishbone this way. If you really want to retain the A spindles and tie rod, maybe you can tweek the arms up a bit for clearance above the wishbone. Or maybe tweek them down a lot for more clearance under the wishbone. Do you know what type of caster angle you are creating with your setup? If not, read up on caster, then make sure you have in the 5 to 6 degree range with the car sitting at the rake it will drive at upon completion. You may need to pie-cut the wishbones to get the right caster. Once you open the can of worms, they all crawl out.
I'm building this "toy" out of collected parts. 30's motor & frame 28 CCPU body chopped to make it an RPU with 8" extension and with all the parts the bones were already split and I liked the look so I went with it. I think I'll research the dropped axle more and recalculate to see which way to go. It also has a shortened pitman arm, doesn't that work better with a dropped axle? As for the spindles the hydraulic brakes I bought have had the backing plates modified to fit the original spindles and would have to be modified again to readapt them to 40 spindles.
If you are going to look at drop axles and want to keep your modified backing plates, look at 32-34, or 35-36 spindles. They have the same bolt pattern and center bore as the model a, but have integral tie rod arms like 37-41 spindles, the 32-34's also have an integral arm for the drag link. Posted using my Lil' Orphan Annie Secret Society Decoder Pin
Nobody here knows me, I've not posted an introduction yet, but I suppose I should. I've been lurking around in the shadows here for a couple years and finally signed up last winter some time. I see a spot where I might interject something useful that nobody seems to have thought about or at least not mentioned. When the wishbone is not split all it does is locate the kingpins in a square relationship with the frame and set the caster angle. After it is split and the ends attached to each frame rail, it still does the first two jobs, but it also makes the axle a sway bar. Using a hard right turn as an example, the left frame rail will rise and the right rail will drop taking the ends of the split wishbone with them and forcing the axle to twist, just like a sway bar does. How much effect this will have on cornering remains to be seen. The bones make a rather long lever and the beam axle is not very resistant to twisting, particularly if it has had the web drilled. Still, there should be some benefit to flatter cornering, especially with a lightweight banger car. Just my 2 cents worth and something to consider anyway.
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